1. Field of the Invention
The present invention relates to magnetic separation generally and, more particularly, but not by way of limitation, to a novel apparatus that permits the automatic separation of magnetic components in a laboratory microplate.
2. Background Art
In the field of biology, there are requirements for the separation of one constituent from another. Some of e more commonly used methods are centrifugation, filtration, and magnetic separation. Centrifugation uses centrifugal force to provide separation by elements of mass. Filtration on provides separation by size. Magnetic separation uses a magnetic field to attract and hold magnetic particles, or magnetic beads, so that the supernate in which the suspended material is disposed can be removed.
Magnetic beads are particularly useful in immunoassays. Constituents of interest may be coated on the surface of paramagnetic particles. Using an applied magnetic field, the beads may be congregated and retained from the surrounding liquid reagents of reactants. U.S. Pat. No. 5,779,907, issued Jul. 14, 1998, to Yu, and titled MAGENTIC MICROPLATE SEPARATOR, describes a means and method of providing magnetic separation. As described in the patent, a laboratory tray, or microplate, containing a number of vertical wells is placed on a fixture having a number of upstanding cylindrical magnets. The arrangement of wells and magnets is such that each magnet is disposed adjacent four of the wells. Thus, a 96-well plate requires a fixture that has 24 magnets. The magnetic components in the wells are attracted to the sides of the wells adjacent the magnets. The supernate in the wells can then be removed. The apparatus described by Yu is entirely satisfactory for manual use; however, it does not meet the need of processing the large numbers of samples that are required in the fields of genomic and drug discovery research. Automation is required for processing large numbers of samples.
Conventionally, in automated magnetic separation systems, a robotic arm moves the laboratory trays over a fixed plate of magnets. While this provides an improvement over the manual method, it requires an additional positioning of the laboratory tray.
Accordingly, it is a principal object of the present invention to provide an apparatus for magnetic separation that does not require a separate step of positioning of the laboratory plate.
It is a further object of the invention to provide such an apparatus that can be remotely and automatically controlled.
It is an additional object of the invention to provide such an apparatus that can be economically constructed using conventional techniques.
It is another object of the invention to provide such an apparatus that can be part of a robotic liquid handling system.
Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.
The present invention achieves the above objects, among others, by providing, in a preferred embodiment, an apparatus for automated magnetic separation of materials in laboratory trays, comprising: a frame upon an upper surface of which a multiwell laboratory tray may be placed, a base plate on which is mounted a plurality of upstanding magnets disposed below said upper surface; and means to raise said base plate such as to insert said upstanding magnets into interwell spaces in said laboratory tray.